Digestive Health Inflammatory Bowel Disease Treatment Side Effects of Flagyl (Metronidazole) This antibiotic is used to treat infections and pouchitis in j-pouches By Amber J. Tresca facebook twitter linkedin Amber J. Tresca is a freelance writer and speaker who covers digestive conditions, including IBD. She was diagnosed with ulcerative colitis at age 16. Learn about our editorial process Amber J. Tresca Medically reviewed by Medically reviewed by Robert Burakoff, MD, MPH on August 03, 2020 linkedin Robert Burakoff, MD, MPH, is board-certified in gastroentrology. He is the vice chair for ambulatory services for the department of medicine at Weill Cornell Medical College in New York, where he is also a professor. He was the founding editor and co-editor in chief of Inflammatory Bowel Diseases. Learn about our Medical Review Board Robert Burakoff, MD, MPH on August 03, 2020 Print Table of Contents View All Table of Contents Uses Common Side Effects Check With Your Doctor Other Important Considerations Flagyl is a type of antibiotic and an antiprotozoal medication that is used to treat bacterial infections in the body. The generic name for this antibiotic is metronidazole, and it also may be sold under the name protostar. Flagyl may be used to treat infections occurring in the skin, reproductive organs, and the digestive tract. It is often taken as a capsule, but it can also be given through an IV in a hospital or doctor's office. Verywell / Gary Ferster Uses Flagyl is sometimes used to treat Crohn's disease, which is one form of inflammatory bowel disease (IBD), especially when the disease is affecting the perianal area or only the colon (large intestine). It may also be used to treat pouchitis, which is a poorly-understood condition that occurs in people who have had surgery to remove their large intestine and create an internal pouch from the small intestine, which is called a j-pouch. Pouchitis tends to occur more often in people who had the surgery to treat ulcerative colitis than in the people who had the surgery to treat another condition in the colon, such as familial adenomatous polyposis (FAP). Flagyl is also used to treat an infection in the digestive tract with a bacteria called Clostridium difficile. C difficile infections are becoming increasingly prevalent and are especially dangerous when they occur in people who have IBD. For treating pouchitis and C difficile, Flagyl is sometimes taken for long periods of time, and perhaps along with another antibiotic, or alternating with another antibiotic. Flagyl is also used in combination with other drugs to treat an infection with Helicobacter pylori. H pylori infects the stomach and can lead to stomach ulcers. Flagyl And Alcohol It is extremely important that people who take Flagyl not drink alcoholic beverages until at least 3 days after stopping the drug. Flagyl affects the way alcohol is broken down, and that leads to symptoms of nausea and vomiting, which can be severe. Overview of Flagyl (Metronidazole) Common Side Effects Check with your doctor if any of the following side effects continue or are bothersome: diarrheadizziness or lightheadednessheadacheloss of appetitenausea or vomitingstomach pain or cramps Less Frequent or Rare Check with your doctor if any of the following side effects continue or are bothersome: change in taste sensationdryness of mouthunpleasant or sharp metallic taste Check With Your Doctor Less common: any vaginal irritation, discharge, or dryness not present before use of this medicineclumsiness or unsteadinessmood or other mental changesskin rash, hives, redness, or itchingsore throat and feverstomach and back pain (severe) For injection form: Pain, tenderness, redness, or swelling over vein in which the medicine is given Notify Your Doctor Immediately It's not common, but some people experience a tingling in their hands and feet when taking Flagyl. If that happens, stop taking the drug immediately and call the doctor to figure out what to do next.Less common: Numbness, tingling, pain, or weakness in hands or feetRare: Convulsions (seizures) Other Important Considerations All antibiotics can reduce the effectiveness of oral contraceptives ("the pill"), so women using this as their birth control method should use a backup method until after finishing the course of antibiotics. Flagyl can also sometimes cause urine to turn dark brown, but this is not dangerous and it goes away after the drug is stopped. Flagyl, and all other antibiotics, should always be taken until the prescribed dose is finished. If there are concerns about the potential adverse effects of this or any other drug, check with a pharmacist and/or physician before discontinuing it. Other side effects not listed above may also occur in some patients. Check with a doctor about any other effects that occur. This information is meant only as a guideline—always consult a physician or pharmacist for complete information about prescription medications. Was this page helpful? Thanks for your feedback! We're providing tips on how to take better care of your gut. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. G.D. Searle LLC Division of Pfizer Inc. FLAGYL- metronidazole tablet, film coated. Updated July 2018.